Continuous aim gun control mechanism



Oct. 20, 1953 H. ERNST ETAL 2,655,338

commuous AIM cum CONTROL MECHANISM Filed May 29, 1936 12 Sheets-Sheet 1 E g g A INVENTOR. #4: fQ/YJ'I BY Hwy/9. k444i) ATTORNEY.

H. ERNST ET AL CONTINUOUS AIM GUN CONTROL MECHANISM Oct. 20, 1953 12 Sheets-Sheet 2 Filed May 29, 1936 12 Sheets-Sheet 3 Filed May 29, 1936 v 3% O g mm MWW ATTORNEY.

Oct. 20, 1953 H. ERNST ET AL 2,655,838

CONTINUOUS AIM GUN CONTROL MECHANISM Filed May 29, 1936 12 Sheets-Sheet 4 INVENTOR. 13 77/! J44 267 2% J45 /f y y fp y f 26! BY ,4/701 fifflm/zfr ATTORNEY.

Oct. 20, 1953 H. ERNST ETAL CONTINUOUS AIM GUN CONTROL MECHANISM l2 Sheets-Sheet 5 Filed May 29, 1936 Oct. 20, 1953 H. ERNST ETAL 2,655,838

CONTINUOUS AIM cum CONTROL MECHANISM Filed May 29, 1936 12 Sheets-Sheet 6 ATTORNEY.

Oct. 20, 1953 H. ERNST ET AL 2,655,338

commuous AIM GUN common MECHANISM v 12 Sheets-Sheet 7 Filed May 29, 1936 ATTORNEY.

Oct. 20, 1953 H. ERNST ET AL 2,655,338

commuous AIM GUN CONTROL MECHANISM Filed May 29, 1936 12 Sheets-Sheet 8 .illllllWflblllllflillllllll 2/0 liq/4 INVENTOR.

' #4: fwvrr BY /%Mi IJ l ATTORNEY.

Oct. 20, 1953 H. ERNST ET AL cou'rmuous AIM cum CONTROL MECHANISM 12 Sheets-Sheet 9 Filed May 29, 1936 Z NW N a 7\mw J J m w 07 fl w 1/ W i/ 5 2 fi W K /,/4

Oct. 20, 1953 H. ERNST ET AL 2,655,838

CONTINUOUS AIM GUN CONTROL MECHANISM Filed May 29, 1936 12 Sheets-Sheet l0 INVENTOR.

ATTORN E Y Oct. 20, 1953 H. ERNST ETAL CONTINUOUS AIM GUN CONTROL MECHANISM l2 Sheets-Sheet 11 Filed May 29, 1936 ATTORNEY.

n V 2 H Q. 6 or 1 9/0 OJ h F Q OJ M A I, 0 OK p 4 F bzf V 5 A M i Oct. 20, 1953 H. ERNST ET AL 2,655,838

CONTINUOUS AIM GUN CONTROL MECHANISM Filed May 29, 1936 12 Sheets-Sheet l2 ATTORNEY.

Patented Oct. 20,

UNITED STATES PATENT OFFICE co'nriivtious AIM any ooN'raoL MECHANISM Hans Ernst and Amos H. Hawley; Cincinnati, Ohio, assignor's, by mesne assignments, to the United States of America. as represented 40 Glaims;

This invention relates to sensitive control mechanisms for use in connection with gun mounts for the purpose of controlling the pointing of a gun from a remotely located director.

Although mechanisms have heretofore been provided for interconnecting a director with a gun for remote control thereof, great difliculty' has been encountered in maintaining the correct target pointing relationship between director and gun during the adjustment or relative movement thereof, as occasioned, e. g., by the roll of the ship. With certain of these devices, a correct positional agreement might have been obtained when the ship was relatively stationary, as when at the top or bottom of a roll, or when in calm water, but not while the motion was taking place.

In the attempt to maintain correct positional agreement by means of a mechanism responsive to a given relative angular movement of the director, thereby driving the gun through the same angle without overrun and without hunting, auxiliary devices, such as anticipating mechanisms, high powered brakes and anti-hunting mechanisms became necessary.

The present tendency in fire control mechanisms is to use stabilized directors mounted independently of the ship so that the gun and director are no longer responsive to ship roll in the same way, it being understood that the ship is considered as having continuous sinusoidal inotion clue to the sinusoidal motion of the sea waves. In other words, the directors, or the optical systems thereof, are gyroscopically balanced, which means that there is a continuous relative movement or oscillation between the director and ship.

If now, the ship is assumed to be stationary, then the director may be considered as a continuously moving element, which means that if the gun is to follow the director it must also be continuously moving with respect to the ship. Prior mechanisms, designed only on the principle of positional agreement without respect to the rate of motion, become inadequate for use with stabilized directors, due to the diflicultics of lag and overrun which normally exist therein.

It is, therefore, an object of this invention to provide an improved means for maintaining coii tinuous accurate aim of a gun mounted on an unstable carrier such as a ship, plane, or the like.

A further object of this invention is to provide improved coordination or punctuality of a gun with respect to its director in such a manner that the gun will substantially accompany the direc Wine tor at all times rather than follow it, thereby eliminating lag either during continuou movement or at reverse.

A further object of this invention is to provide a mechanism adapted to measure the speed of oscillation between a stabilized director and its supporting carrier and impart the desired proportion of that speed to the final actuator of a gun and thereby maintain the gun and director aimed at the same target.

A still further object of this invention is to provide a mechanism of the character set forth which will automatically correct for variations in phase and amplitude of gun movement with respect to director movement.

Still another object of thi invention is to provide an improved mechanism for use in connection with a gyroscopic or otherwise stabilized director which will automatically correct the aim of a gun as it is disturbed by undesirable movements of the carrier upon which it is mounted, and which mechanism may also be utilized to effect deliberate changes in the aim of the gun in accordance with deliberate adjustments of the director.

Another object of this invention is to provide a mechanism of the character set forth which may be utilized either for controlling the training or the elevating of a gun and which includes master controls whereby the gun may be automatically synchronized with a new director as well as auxiliary devices for local manual control of the gun,- eithcr direct or through servomechanisms.

Other objects and advantages of the present K invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, with out departing from or exceeding the spirit of the invention.

Referring to the drawings in which like reference numerals indicate like or similar parts:

Figure l is an elevational view partly in section showing a general assembly of the mechanism involving the principles of this invention.

Figure 2 is an enlarged detail section as viewed on the line 22 of Figure I.

Figure 3 is a section on the line 3-3 of Figure 2.

Figure 4 is a section on the line 4-4 of Figure 3.

Figure 5 is a section on the line I5 of Figure 3.

Figure 6 is a section on the line 66 of Figure 3.

Figure 7 is a section on the line 1-I of Figure 3.

Figure 8 is a section on the line 8-8 of Figure 2.

Figure 9 is a detail section on the line 9-9 of Figure 8.

Figure 10 is a section on the line Ill-ll) of Figure 2.

Figure 10A is a section on the line "IA-10A of Figure 2.

Figure 11 is a section on the line lll I of Figure 2.

Figure 11A is a section on the line I lA-I IA o Figure 2.

Figure 12 is a section on the line l2-l2 of Figure 8.

Figure 13 is an enlarged detail section showing the interconnection of the manual and power control means to the control screw of the variable speed hydraulic unit.

Figure 14 is a section on the line 64-14 of Figure 13.

Figure 15 is a section on the line i5-i5 of Figure 2.

Figure 16 is a section on the line iii-l6 of Figure 1.

Figure 17 is a section on the line l'l--I'l of Figure 16.

Figure 13 is a section on the line 13-18 of Figure 16.

Figure 19 is a section on the line l9l9 of Figure 2.

Figure 20 is a section on the line 2fl20 of Figure 17.

Figure 21 is a section on the line 2l--2l of Figure 2.

Figure 22 is a section on the line 2222 of Figure 16.

Figure 23 is a section on the line 2323 of Figure 2.

Figure 24 is a block diagram of the operating connections between the director and final actuator of one of the gun mechanisms.

Figure 25 is a view of the mechanism for measuring the speed of oscillation between the director and carrier and applying a correction thereto for variations in phase.

Figures 26 to 30 are views showing sinusoids which graphically depict movements of the various elements in the train of operating parts between the director and gun.

Figure 31 is an enlarged detail view of an adjustable double throttle valve.

Figure 32 is a general diagram of the entire control system.

Figure 33 is a view showing the connections to the roller path error correcting unit.

Figure 34 is a rolled out view of the servo-valve shown in Figure 13.

Figures 35, 36 and 37 are sinusoids which graphically depict the manner of applying corrections for phase and amplitude of gun movement as respects director movement.

Figure 38 is a detail section on the line 38-38 of Figure 2.

Prior to consideration of the specific details of this invention, a few preliminary matters should be discussed in order to understand more fully the particular oifice of this invention.

In the remote control of guns mounted on unstable carriers, such as ships. planes and the like,

4 there is a so-called director unit which includes, among other things, an optical piece, by which the sighting or aiming is done, and an immediate support therefor which together may be termed herein as the director. The director is so mounted and supported as to be held in a horizontal plane, as by the use of gyroscopic or other means, whereby undesirable movements of the carrier, such as the pitch and roll thereof, will not be transmitted to, and thereby disturb the aim of, the director, whereby the director may be said to have continuous aim as respects these undesirable movements.

In addition, it should be pointed out that even although the director is thus stabilized in a horizontal plane means are provided whereby a portion of the director, such as the optical piece, may be deliberately adjusted in a. vertical plane and the entire director deliberately adjusted in a horizontal plane, for the purpose of changing the aim.

The director unit also comprises two output shafts, one of which may be termed the elevating control element and the other the training control element, and these shafts are connected through mechanism contained in the director unit for response to all movements of the director, whether of the deliberate or of the undesirable variety as set forth above.

This connecting mechanism, which is of a complicated nature and forms no part of the present invention, includes various devices for introducing a number of corrections necessary to the proper determination of the final correct trajectory of the fired shell, and which are of such a nature that they are conventionally introduced at this point.

From this brief explanation it should be apparent that the director unit contains mechanism which acts to resolve the relative movements, whether undesirable or deliberate, between the carrier and the director into corrected motions of the two output shafts, which motions are in such form that they may be utilized without further change for control of the gun.

Since the final connection to the gun in both the elevating and training mechanisms usually involves a 36 to 1 reduction, the aiorenlenticned connecting mechanism in the director includes a 1 to 36 step-up, whereby the motion of the output shafts is really the motion that is imparted to the final actuator of the training or elevating mechanisms. For positional purposes, to be described later, the output shaft is connected through a 36 to 1 reduction to a second shaft which is utilized for master control purposes.

The office of this invention is to measure the corrected speed of oscillation in both vertical and horizontal planes of the director relative to the carrier, whether occasioned by undesirable movements of the carrier, or by deliberate movements of the director. which corrected speed of the director is the same as the output shafts of the director unit, and to impart the same to the final actuators of the training and elevating mechanisms.

In order to simplify the explanation, the relative movement between the ship and the director will be referred to hereafter as the motion or movement of the director, because it is the initiating force or movement of the system.

Referring now to the specific features forming the subject matter of this invention, there is a main operating or speed matching circuit, which will be more readily understood by referring to the block diagram shown in Figure 24. In this figure the reference numeral l represents the director and the reference numeral H represents the final actuator which may be of either the training or elevating mechanism. It will be seen that the circuit includes a concatenation of devices with intervenin connections, through which a power medium may be conducted, and these connections may be considered as constituting motion transmitting connections because they serve to transmit motion from the director to the gun in spite of the fact that the power may be amplified as it passes from one device to another.

This amplification, of course, is necessary if the small torque or force developed by movement of the director is to be transmitted through a distance and utilized to cause displacement of an unwieldy gun.

The speed matching circuit functions as follows: the angular motion or oscillation of the director is transmitted over the connection [2 to a receiving unit l3, which serves to measure the speed of angular movement of the director, and supervise the setting of a variable speed gear M for movement thereof at a suitable proportional speed, depending upon the ratio of the subsequent gear connection to the gun whereby the angular speed of the gun will be the correct function of the angular speed of the director. This supervision is effected through the medium of a servo-motor control unit l5 operable by the receiver to determine power rotation of the variable speed gear. A feed back i6 from the variable speed gear completes the servo-control.

The arrows indicate the direction of the flow of power. The feed back l6, and the infeed from the receiving unit are connected to a common member, whereby the speed of the output is matched with the speed of the input.

It is obvious that. due to the inertia of so many movable parts, and the sequential movements to be eifected, a time lag is inherent and that the gun-although it may finally move at the corrected speed of the directon-will do so at a later time with the result that the sinusoidal motion of the gun will be out of phase with the sinusoidal motion of the director, and furthermore, the amplitude of gun movement may also differ from that of the director.

It, therefore, becomes necessary to provide in parallel with the foregoing circuit, a position matching circuit comprising the detecting mechanism I1 having direct connections i8 and iii to the director and gun respectively, whereby position differences between the director and gun may be immediately detected and utilized through connections 20 and 20 to apply a corrective eifect to the receiving unit of the speed matching circuit in such a manner as to synchronize both the phase and amplitude of the two movements.

Thus the mechanism of this invention constitutes, in its simplest form, a power train through which energy is directed from the director to the gun to effect a rate of angular movement of the gun in accordance with the corrected. rate of angular movement of the director; and means responsive to position differentials between director and gun to correct independently for both phase and amplitude, and all based on the principle that if the phase and amplitude of the sinusoidal motions of two objects are synchronized, the objects will necessarily move at the same speed, and instep with one another.

The specific construction of the specd matching circuit and of operation now be explained.

Referring to Figure 82, there is diagrcaily illustrated a gyroscopically balanced director, including the telescopec'l and its immediate support '21. Since the details of the gyroscopic stabilizing system and the connecting mechanism heretofore referred to, and which includes the various connecting devices, form no part of the present invention, they are diagrammatically illustrated by the rectangle 22, from which emerge the output shafts, of which the shaft 23 may be considered as the trainingc'ontrol element and the shaft 23' the elevating control element.

The entire control system shown in Figure 32 is illustrated as connected to the shaft 23 for training control "and it is to be understood that a duplicate of this system is also connected to shaft 23'.

As previously explained, each of these shafts are rotated at a 36 to 1 ratio as respects gun movement, and each shaft drives, through a '86 to 1 reduction, a. second shaft which operates a master control circuit.

Referring back to the speed matching circuit, the shaft 23 has attached thereto a pair of rotors on which are wound the field coils 24 and 25 of two self-synchronous electrical transmitters 24 and 25' which also have stator coils 26 and 2'1. The field coils are excited by a source of alternating current, represented by the power lines 28 and 29.

The stator coil 21 has a polycircuit connection through lines 30, 3! and 32 to the stator coil 33 of the self-synchronous receiver indicated generally by the reference numeral 34 of the speed matching circuit. This receiver has a rotor 35 attached to an output shaft 35. These selfsynchronous devices operate on the principle that when the field coil of the transmitter is rotated relative to the stator coil an electrical disturbance is set up which is transmitted to the receiver causing rotation of the receiver rotor through the same angular movement that the transmitter rotor was moved. Since there is no appreciable lag in such a system, it will be apparent that the output shaft 36 will move in substantial unison with the input shaft 23.

Referring now to Figures 3, 4, 5, 6 and 7, there is shown a portion of the receiving unit l3 comprising a combination pump-motor unit, and power amplifying means, whereby the output shaft 36 of the self-synchronous receiver 34 may be utilized to control rotation of the motor. As the shaft 36 rotates, it causes synchronous rota-- tion of the motor shaft which, in turn, causes the pump to operate and transfer fluid from one, of a pair of control lines, into the other thereof. It is to be remembered that the self -synchronous device 34 can develop very little torque, and therefore a form of power amplifying means has been provided which will operate in such a manner that it will not cause any appreciable load or resistance to the rotation of shaft 36. These various parts are supported in a housing 31 having an opening 38 at one end in which is mounted the synchronous device 34. The housing has a flange 39 by which it may be suitably secured to a support 40.

The housing 31 has a central bore 4| in which is fixed a sleeve 12 for supporting a rotatable member 43. This member has an enlarged head 44 in which is formed a cross bore 45 forreceiving a sleeve 46, which is fixed against longitudinal movement in the bore. The ends of this sleeve are closed by threaded plugs 41 to form a chamber for a movable valve member 48. To the shaft 36 there is attached a dished highly sensitive rotor 49 which has an annular face 50 movable relative to ports and 52 formed in the head 44. As shown in Figure 6, the upper portion of the face 50 is cut away to form shoulders 53. These shoulders are so located that they normally bisect the ports 5! and 52 so as to restrict the escape of fluid from the port, and in reality constitute a form of hydraulic resistance. When shaft 36 rotates, it varies the values of these resistances to cause actuation of the valve member 48, which in turn controls operation of an hydraulic motor.

In order to perfect this control, another pair of variable hydraulic resistances are provided, and these are formed on the valve member itself. The sleeve 46 has a pressure port 52' which is connected by a cross bore 53' to an annular groove 54 formed in the periphery of the rotatable member 43. This groove is continuously supplied with pressure from a channel 55 which may be connected to any suitable pump 56 as diagrammatically illustrated in Figure 32.

Opposite the port 52' the valve member 48 has a spool 51 formed thereon, and each end of the spool is slightly reduced in diameter at 53 and 59, whereby the fluid entering the pressure por will be divided and part will flow past portion 58 and the other part will flow past portion 59. When the spool 51 is central of port 52' the value of the hydraulic resistances created by the portions 58 and 59 will be equal.

Beyond the portion 58 there is formed an annular groove 60, which is connected by a cross bore BI and longitudinal bore 62 to the chamber 63 formed at one end of the valve. This chamber is connected by a radial passage 54 to the port 5|.

Similarly, beyond the portion 59 is formed an annular groove 65 which is connected by cross bore 66 and longitudinal bore 61 to the chamber 68 formed at the other end of the valve. This chamber communicates by means of a radial passage 69 to port 52.

Thus the fluid from the pump 56 divides at port 52', one portion flowing through the hydraulic resistance formed by the part 58, annular groove 60. and the interdrilled passages to chamber 63. The pressure in chamber 63 will be less than the pressure at port 52' due to the drop in pressure caused by the hydraulic resistance. This pressure will act on one end of the valve member 43, tending to shift the same. The fluid in chamber E3 will escape through the radial channel 64 to port 5!, and a further drop in pressure will occur due to the hydraulic resistance at the shoulder 53.

The other portion of the fluid will flow through the hydraulic resistance formed by the portion 59, annular groove 65, and the interdrilled passages to chamber 68. The pressure in chamber 58 will be less than the pressure at port 52, because of the drop caused by the hydraulic resistance. The pressure in chamber 68 will act to shift the valve in an opposite direction, or in other words, against the pressure created in chamber 63. The fluid in chamber 68 will escape through the radial passage 69 and there will be a further pressure drop in the fluid escaping through port 52, due to the resistance at the shoulder 53.

It will now be seen that as the fluid leaves port 52 it passes through two parallel branches, in each of which is formed a pair of serially arranged hydraulic resistances with a pressure chamber intermediate said resistances. The hydraulic principle involved is that if each of one pair of serial hydraulic resistances has the same value, the pressure in the intermediate chamber will be onehalf of the incoming pressure, or in other words, one-half of the pressure at port 52. It will, therefore, be seen that if all four of the hydraulic resistances involved have the same value, the pressure in chambers 63 and 68 will each be one-half of the incoming pressure and therefore no movement will be imparted to the valve member 48, because the forces acting on opposite ends of it are equal. Assuming such a condition to exist, it will now be apparent that if the member 49 is rotated, the resistance to the escape of fluid at one of ports 5!, 52 will be diminished and at the other will be increased, thereby changing the relative pressures in chamberg 63 and 6d and thereby causing movement of the valve member 48.

This valve movement is utilized to control actuation and reversal of an hydraulic motor, and to this end the valve member 45 may shift in either one of two directions from the central position. It should also be noted that as the valve member shifts it changes the values of the hydraulic resistances at 58 and 59, and the valve will shift only far enough to equalize again the value of the first of the serial resistances in each pair, to the respective second serial resistance of each pair. When this occurs, the opposing pressures are again equal and the valve member will be held in a predetermined new position. When the hydraulic motor is energized, it bodily rotates the member 43 so as to reposition ports 5i and 52 in a central position relative to the new position of the shoulders 53, which thereby causes repositioning of the valve member 48 to stop actuation of the hydraulic motor. It will thus be seen that this operates after the manner of a servo-mechanism.

The hydraulic motor, indicated generally by the numeral 15', consists of a plurality of plungers Ill which are radially arranged, as shown in the upper part of Figure '7, and there are actually seven of these plungers, although any suitable number can be utilized. The ends of these plungers engage the periphery of an eccentric II which is anti-frictionally supported, as by balls 12, on an eccentric member 13 having bearing portions T4 and 15 formed on opposite ends thereof, and axially aligned with the axis of rotation of the rotatable member 43. The journals l4 and 15 are anti-frictionally supported in the housing 31 on bearings i and H.

The journal I5 has a pair of axially extending lugs 78 which interfit in diametrically opposed slots formed in the periphery of an interconnecting ring 19. This ring has another pair of diametrically opposed slots 80 formed in the periphery thereof, but in degree phase relation to the first pair of slots, into which fits a pair of lugs 8| projecting from the end of member 43. This form of driving connection permits small relative longitudinal and lateral movement between the parts, but the fits are such that there is no lost motion in the angular movement of the parts.

The end of each motor cylinder 82 is connected by an L-shaped passage 83 to a longitudinal groove 84 formed in the periphery of the sleeve 42. As shown in Figures 3 and 4, each groove termmates in a port adjacent the periphery of V ,e rotatable valve member 4a. This member has a pair of grooves 83 and 31 constituting pres: sure and exhaust chambers, which are alternately connected upon rotation of the member 43 with difierent groups of ports 8-5, whereby one group of pistons lIi is subjected to pressure while the others are connected to'exhaust.

A pair of longitudinally extending holes 88 and 89,, Figure 6, connect the spaces 86 and Ill. respectively, to ports 90 and M of the control valve, It will be noted from Figure 6, that the channel 88 is connected by a cross bore 92 to the port 91. The control valve has a pressure port 93, which is in communication, with the supply line 55; and a pair of exhaust ports 84 and 95. Each exhaust port includes an annular groove which is intersected by a drilled hole 96, as shown in Figure 6, which communicates with the interior of the housing. A spool 91 substantially closes port 93 when the plunger 4a is in a central position, and additional spools spaced at opposite sides of the central spool substantially close ports 94 and 95. When the valve member 48 is shifted in either direction pressure from port 93 will be admitted to either channel Bl or 89, while the other is connected to exhaust to cause operation of the motor. pcration of the motor will cause rotation of the member 43 relative to the sleeve 42, as shown in Figure 4, and thereby act as a distributing valve to keep the motor in operation.

The motor III is utilized to actuate a pump generally designated as 93 which is combined in the same structure and comprises a plurality of pump plungers 98 which are alternately spaced with respect to the motor plungers, as shown in Figure 7, and which lie in a plane ellset with respect to the plane of the motor plungers. The ends of the pump plungers contact the same eccentric member II so as to insure that all parts of the mechanism operate in timed relation with one another and thus prevent any lag in the system.

The end of each pump cylinder 89 is connected by an L-shaped passage Hill, as shown in Figure 3, to a longitudinally extending groove IOI formed in the periphery of the sleeve 42, each groove terminating in a port IE2, as more particularly shown in Figure 5. Itwill be noted that these grooves are spaced intermediate the grooves 84. The rotatable member 43 is provided, with a second pair of oppositely positioned grooves Hi3 and I04 which serve as a distributor valve to alternately connect the ports to longitudinally extending bores I05 and I06. These bores terminate in annular grooves I01 and ma respectively which are in constant communication with ports I09 and III).

Thus, the motion of the director causes rotation or oscillation of shaft 23 and the connccted rotors and coil 24 which, sets up a reaction in the electrical circuit and causes a similar rotation or oscillation of shalt 36 remot ly located with respect to the director. The disc 4!. attached to shaft 36, caus s. through the hydraulic amplification means. a shifting of areversins valve which controls reverse operation or the motor Ill. The pistons of this motor act on the eccentric II to rotate the same. and retattoo of the eccentric reciprocatcs the pluneers of pump 98. In, addition. rotation of the cocen rie causes rotation of member 43 and inteeral head 64. to cause a follow-up of ports SI and 52 relative to the shoulders on disc 49 10 whereby a servo-acti n is produced to stop the motor IIL' any time that the discv 49- stops, The pump 88, transfers fluid from one side to the other of a circuit now to be explained.

This, circiut in elemental form is more part u a lv shown in Figure 25 and is similar in principle of operation to the. circuit which controls the position of the reversing valve ll shown in Figure 3 In other words, the pump 56 supplies fiuid under pressure through a branch line I to a pair or hydraulic resistances indieated, generally by reference numerals II! and II3 from which the fluid flows in parallel lines H5 and III respectively to a second pair of hydraulic resistances, indicated generally by the reference numerals H6 and II I, and then through a. common return line I III to reservoir II9 whereby the fluid may be recirculated by pump 56. It is to be understood that fluid pres sure is continuously flowing through this circult, in the manner Just described during operation of pump 56.

The hydraulic resistances I12 and H3 are form d. y el shtly reducing the diameter of the valve plunger I20, adjacent opposite ends of a central spool IZI. The fluid flowing through the hydraulic resistance H2 is collected in groove I22 and passes through a bore I23 to the chamber I24 located at one end of the valve housing I25 communicating with line H5. The fluid flowing through the hydraulic resistance 3 is collected in the groove I28 and passes through the bore I21 to the chamber I28 located at the other end of valve housing I25 and communieating with line H4.

The hydraulic resistances H8 and II? may be formed by slightly tapered portions on the plunger I29 at oppositeends of the control spool I30. This time, the flow of fluid in the two lines is combined and delivered to a common return line. The. plunger I29 is adjusted and held in a fixed position by adjusting screws I3I which are threaded in each end of the housing I32 containing plunger I29. By means of these adjusting screws the resistances H6 and II! can be inversely varied so as to automatically adjust the position of plunger IN and centraL izle spool I2I with respect to port I33.

Since the pressures in chambers I and I28 are equal, the plunger I20 will be held against movement. It will be evident, however, that if part of the fluid flowing in line H5 ould be transferred into line I, the pressure in the lat er line would rise and the pressure in line H5 would drop. thereby causing a drop in pres.- sure in chamber I24 and a rise in pressure in chamber I28, This, in turn, would cause the valve plunger I20 to shift because of unequal pressures on its ends.

, This shifting movement would continue until the hydraulic resistances III and I13 have been inversely adjusted to increase the flow from. port I33 to chamber I24 and decrease the flow from port I 33 to chamber I28, until the pressures in these two chambers again became equal. the valve plunger I20 could be made to shift from its central position m either direction by transferring fluid from one of lines H4, H5 to the, other.

Furthermore, the amount of this shifting move- U161, would be in direct proportion to the rate of transfer of fluid. This basic circuit is therefore set up, and the lines H4 and H5 are connected by channels I34 and I35 to, ports I and IIB or the pump Figure 3.

It should now be evident that the oscillation of disc 49 in Figure 3, which is almost directly proportional to the oscillation of the ship, will cause, through hydraulic amplification means, oscillatory action of motor cylinders 16 on eccentric 13, which, in turn, will cause the pump 98 to transfer fluid alternately in opposite directions between lines H4 and H5.

Since all of these motions are sinusoidal in nature they may be plotted, and the curves shown in Figure 26 are graphical representations of these various motions. In this figure, the sinusoidal curve I34 represents the sinusoidal motion of the ship relative to the director. The point I35 on the ordinate I36 represents the extreme movement of the ship in one direction, and the point I31 of the ordinate I38 represents the other extreme movement of the ship. At the point I30 where the curve I34 crosses the abscissa I40 the rate of motion of the ship will be at its greatest.

It will be noted that the point I36 is halfway between the ordinates I36 and I36; and the ordinate I4 I, passing through this point, may be said to be spaced 90 degrees from ordinate I36 and I36.

Since the train of connections between the transmitter 25' and the metering pump 68 has substantially no lost motion in it, the motion of the metering pump is substantially in phase with the motion of the ship relative to the director and therefore a second sinusoidal curve I42 may be drawn in Figure 26 which is in phase with curve I34, although it may be graphically represented as having a different amplitude so that it may be distinguished from curve I34. At the point I43 where the curve I42 crosses the ordinate I36, the pump will be at one extreme of its motion and therefore will be on the point of reversing, at which time the delivery from the pump will be zero. If, then, another curve, such as I44, is added to Figure 26 to represent the rate of flow from the metering pump 96, this curve will cross the ordinate I36 at the point I45 because at this instant the rate is zero. This indicates that the sinusoid, representing the rate of flow from the pump, will be 90 degrees out of phase with the sinusoid representing the motion of the pump.

Furthermore, it will be seen that when the pump is traveling at its greatest rate as represented by the point I39, the output from the pump is greatest, which means that the curve I44 will intersect the ordinate I4I at I46.

It has also been explained, in connection with Figure 25, that the distance of the valve plunger I20 away from center is in direct proportion to the rate of transfer of fluid, and since the curve I44 in Figure 26 represents the rate of transfer of this fluid, then a curve may be plotted representing the motion of valve I20. This curve will be a sinusoid and is graphically represented in Figure 27 by the line I41. Since the rate of transfer of fluid is greatest at point I46 on the ordinate I4I, so the valve I20 should at this instant be at one extreme end of its movement which can be indicated by the point I40 on the ordinate I4 I, and when there is no fluid being transferred, the valve will be in a central position for reasons previously set forth, and this will be indicated by the curve crossing the ordinate I36 at the point I46 where the ordinate intersects the abscissa I50. By comparison of Figure 2'? with Figure 26, it will be seen that the motion of valve I20 is in phase with the rate of fluid transfer effected by the metering pump 68'. It will also be noted, by a comparison of these two figures, that the motion of valve I20 is degrees out of phase with the motion of the ship as represented by curve I34.

Referring now to Figures 16, 1'1 and 32, the valve I26 has an intermediate reduced portion at I5I formed by flattening the sides of the plungers, so that a connection may be made with the forked end I52 of a floating link I53 which is the speed matching member. This link is pivotally connected at I54 to a servo-control valve plunger I55 which controls actuation of a rotary hydraulic motor I56, which, in turn, controls adjustment of the swash plate of a variable speed hydraulic unit I4, Figure 24. Movement of the swash plate changes the rate of output of the hydraulic unit, and thereby the rate of movement of the gun, and the plate has a central position in which the output of the unit is reduced to zero, and movement from one side to the other of this zero position changes the direction of movement.

As shown in Figures 17 and 32, the servo-control valve, which may be indicated generally by the reference numeral I56, has a pressure port I51 to which is connected a supply line I58. This valve also has a pair of return ports I59 which are connected to a return line I60. Intermediate the pressure port and the two exhaust ports, are ports I6I and I62 which lead to the hydraulic motor. The valve plunger I55 has a pair of annular grooves I63 and I64 formed therein which serve to alternately connect the pressure port I51 to one of the motor ports; and to connect the other of the motor ports to reservoir, thus controlling reversible operation of the hydraulic motor I56.

The ports I6I and I62 are connected by channels I65 and I66 to ports I61 and I68 of a selector valve I69. This valve is more particularly shown in Figure 15 and has a plunger I10 which is movable to three different positions, it being shown in a central position. When the mechanism is set for automatic operation, now under consideration, the plunger I10 is moved to the right of the position shown a sufficient amount to interconnect port I61 with port HI, and port I63 with port I12. Port IN is connected by channel I13 to port I14 of the hydraulic motor I56. The other port I12 is connected by a channel I15 to port I16 of an emergency stop valve I11. The details of this valve are more particularly shown in Figures 8 and 9.

The stop valve has a plunger I18 in which is formed a cannelure I19 which, in the running position of the valve, interconnects ports I86 and I6I whereby the fluid may continue through the valve into channel I82. Channel I82, as shown in Figure 32, is connected to the other port I83 of the hydraulic motor I56. It should now be evident that with the selector valve and stop valve in the positions indicated, the servo control valve plunger I55 will directly control operation of the hydraulic motor I56.

As shown in Figure 13, the output shaft of the motor I56 is connected to shaft I84 which drives a tubular member I85, having longitudinal grooves or splines I86 and I81 formed lengthwise thereof. Anti-friction bearings I90 and I9I serve to support the member for frictionless rotation. The longitudinal slots I86 and I81 serve as guides for the relatively movable cross head I62. This cross head is keyed at I93 to the end of screw I64. The screw is threaded in a nut I65 which is held in the housing I96 against axial movement. The result is that upon rotation of the member 555 by the hydraulic motor I55, the screw I8 1 will be threaded through the nut 195, since the cross head 1.52 can ove relative to the driving member I85.

As shown in Figure 32, the screw 494 is connected by a coupling 13] to the swash plate adjustment rod I98, which is guided fol-axial movement .in the housing I95. .As shown in Figure 1'], the member 198 has an opening I89 formed therein for receiving the ball-shaped end 20 of the swash plate lever 2M, whereby upon axial movement of the member I88 the swash plate will move about axis 202. The hydraulic unit, otherwise known as an hydraulic variable speed transmission gear, is old and well-known in the art and the operative principle may be the same as that shown in Patent No. 924,787., issued to R. Janney, and therefore further description is not believed necessary, except to state that the end 253 may be considered as the pump end which is continuously driven by the electric motor 254, :and the end 205 may be considered as the motor end, which is directly connected to the output shaft 255.

The output shaft has a worm 201 operatively connected thereto and in operative engagement with a. worm gear 258. The worm gear is supported on a shaft 209, which terminates in a pinion II, meshing with the turret bull gear 2ID in a 36 to 1 ratio. It will now be seen that rotation of the shaft 205 will, through the interconnecting gearing, effect rotation of the bull gear and thereby adjustment of the gun in train. Attention is also invited to the fact that the output shaft 205 of the hydraulic variable speed unit has a. gear 2 attached thereto, which intermeshes with a gear 2J2 formed integrally with the nut member I95 whereby the nut is rotated in a direction to cause axial movement of the screw I94 in a. direction opposite to which it is being urged by the motor I56. In other words, this is a form of servo-control whereby the motor I56 tends to move the swash plate in one direction; and the output from the hydraulic unit tends to return it to a central position. In order to maintain continuous movement, however, the screw must have a certain lead over the return movement from the unit output, and for the purpose of illustration :1 lead of approximately 45 degrees has been shown, but it is to be understood that this will vary under difierent operating conditions.

Since the valve member I55 controls the operation of the hydraulic motor I55 and thereby movement of the control screw, and since this, in turn, causes movement of the swash plate, whose position governs the rate and direction of operation of the feed back and thereby rotation of the nut, the relative movement of all of these parts may be considered for the moment independently of the rest of the circuit, and sinusoidal curves may be worked out to rep resent these various motions.

Since the valve member I55 is moved through the medium of the link I53 by the member I20 and since it has been shown that the member I20 has a sinusoidal motion it will be apparent that the member I55 will also move with a sinusoidal motion. Therefore, a. sinusoidal curve 2I3 has been drawn in Figure 2B, and the intersection of this curve at 2 with ordinate 2I5 indicates extreme movement of the valve I55 in one direction, and the intersection at 2I5 with ordinate 2!! indicates extreme movement in the other direction, while the point 2I8, at which 14 the curve crosses the abscissa 219, indicates a central position of the valve. Through these controlling points a sine curve may be drawn to represent oscillation of valve member I55.

Because we are assuming that this motion is continuous, it will be apparent that at the point where the curve crosses the abscissa, the hydrcnlic motor will momentarily stop, because the valve member is in a central position and no flow is going to the motor. Since the screw I94 is directly connected to the motor I56, they may be considered together, and even although their motions are rotative they still may be considered as having definite limits, and when the curve of the valve 455 crosses the abscissa, as at point 2%, the motor will stop and subsequently reverse, and this point may be considered as one end of the movement of the rotary motor and control screw. Therefore. on the ordinate 2:25 passing through the point 2M, may be plotted a. point ill to indicate one end of the motion of the motor which, or course, will be a maximum when measured on the ordinate 220.

It will be apparent that when the valve member I55 reaches one end of its movement, as indicated for instance by the point 214, the motor will be traveling at a maximum speed because the valve is in a maximum opened position, and at this time the curve 222 will cross the abscissa. at the point 223, which point will lie on the ordinate H5. As the valve member returns to its central position the motor will decrease in speed and will stop at the time that the valve reaches a central position, and this condition is indicated by the met that the points 224 and 225 of curves 2 and 222 both lie on the ordinate 226.

Since the motion of the nut H5 is controlled by the motor 155 through the medium of the hydraulic unit, it will be apparent that it the motor I56 has an oscillating or sinusoidal motion, the nut will have a similar motion but since, as previously pointed out, there is a lag between the nut and the motor, a sinusoidal curve, such as 221, which may be added to Figure 28 to indicate the relative motion of the nut, will have a maximum or extreme movement at the point 228 which, for the conditions chosen for illustration, is approximately 45 degrees behind the motion of the motor. This will determine the location of the curve 221 relative to the curve 222 for the motor and thereby relative to the curve 213 .for the valve.

Since the curve 222 represents the motion of the control screw I84, and the curve 221 the motion of the nut I95, and since the difierence of these two motions is the motion of the swash plate lever 2!, these two curves may be algebraically combined to produce a resultant curve which will represent the motion of the swash plate. Thus a curve 225 may be added to Figure 28 to indicate the motion of the swash plate.

Referring now to Figure 1'1, it will be seen that the free end of the swash plate lever 21 has a pivoted connection at 23!) to an osciliatable member MI. This member is movable about an axis 232, and on the opposite side of this axis from the connection 285, the member 2M has a pivotal connection at 238 to the lower end of the floating link I53. The relationship of the relative motions of the various parts is as follows:

As the valve member I 20, shown in Figure 1'7, moves, for instance, to the left of its center position, thereby moving valve member I55, the subsequent resultant effect causes the swash plate to move to the left of its center position and through the inerconnecting member 23I causes movement of the lower end of link I53 to the right, which thereby acts in a servo-relationship to return the valve member I55 to its central position. In other words, the pivot point 233 is always moving opposite to the movement of the valve member I20, tending to return the valve member I55 to a central position. The result of this is that the valve member I55 has actually very little movement, and even when in either one of its extreme positions it is only a few thousandths of an inch away from its central position. The construction of the valve I55 is such that this small movement is suflicient to cause operation of the motor I56 at its highest speed.

In Figure 28 the sine curve 229 can be considered to represent the motion of the pivot point 239 and thereby the motion of the lower end of member 23!. It therefore follows that the point 233, which is on the opposite side of the pivot point 232, will have a similar motion, but the amplitude of this motion will be considerably less due to the difference in length between the lever arm of the point 233 with respect to the center 232; and the lever arm of the point 236 with respect to said center.

Also, since they are always moving in opposite directions, the movement of point 233 will have a 180 degree phase difference with respect to the movement of the point 230. Considering therefore the difference in length of the lever arms and the phase difference, a curve may be plotted representing the motion of point 233. Such a curve, represented by the reference numeral 234, has been drawn in Figure 29 and it will be noted that it is so positioned as to be opposite in phase to the curve 229.

The curve 2I3, representing the motion of valve member I55, may be superimposed on Figure 29, and since these two curves represent the motion of two different parts of the floating linl: I53 and since these two motions are known, a resultant curve 235 can be produced which will represent the motion of the end II of lever I53, and this resultant curve should correspond to the curve I41 shown in Figure 2'1.

If the curve 235 is now superimposed on curve I41 it will establish the phase relationship between all of the curves in Figures 28 and 29 relative to the curves in Figure 26 and thereby show the phase relationship between the curve 221, which may be considered as representing the motion of the gun relative to the ship, and the curve I34 which represents the motion of the ship relative to the director, whereby it may be determined whether these two curves are in phase or not.

The motion of the end I 52 of lever I53, represented by curve 235 in Figure 29, is really the differential produced by the movements of points I54 and 233, and since the lengths of the lever arms of the different points are some of the determining factors, the curve 235 cannot be found simply by adding or subtracting curves 213 and 234, but resort must be had to a formula involving the lengths of the different lever arms. If we let L1 equal the length of the arm between point 233 and point I54 of lever I53, and L2 the length of the arm between point I 54 and the end I52 of lever I53, then it can be mathematically proven that the movement of end I52 where A=movement of point I54 Bzmovement of point 233 By measuring the ordinates of curves 234 and 2I3 at the several points, the movements of points 223 and I54 may be found respectively, and by multiplying each of these by the fractions indicated in the formula and performing the necessary algebraic operations the curve 235 may be found. Attention is invited to the fact that the curve 2I3 is out of scale with respect to the remaining two curves, but this was done to increase the ordinates for the curve 2I3 in order to clearly show the controlling points of the curve.

Since the curve 235, as found in Figure 29, corresponds to the movement of the valve I26, and since the curve I41, as developed in Figure 2'7, also corresponds to the movement of valve I20, these two curves may be superimposed and thereby show the phase relationship of the curve 221 relative to curve I34. For the purposes of this comparison, the curve 221 has been redrawn in Figure 27 in proper phased relation to curve I41 and it will be noted that the point 236 on this curve has a small lag relative to the ordinate I36 which lag is indicated by the reference numeral 231, in addition to the degree phase difierence between the two curves. The 180 degree phase difference is correct because the transmitter rotor 25, shown in Figure 32, moves with the ship, and the gun must be moved in opposite phased relation to the ship in order to maintain a given position.

It will now be seen that with the apparatus thus far described the gun, although fully responding to every movement of the ship, relative to the director, will yet have an inherent lag.

In order to overcome this lag a position matching system has been provided which will measure the amount of the lag and apply a corrective factor to nullify it.

Referring now to Figure 32, this mechanism includes the synchronous electrical transmitter including the stator coils 26 and the rotor 24, which are relatively movable simultaneously with relative movement between the rotor 25 and the stator coils 21 previously described. The stator coils 26 are electrically connected by lines 238, 239 and 240 to the stator coils I of a second receiver having a rotor 242. The rotor 242 is con nected to shaft 243 which, as shown in Figure 2, has a dish-shaped disc 244 attached to the end thereof. This disc also has an annular face which moves relative to ports 245 and 246 to control the proportional values of the hydraulic resistances at these two ports. These ports are connected by interdrilling 241 and 248 to annular grooves 249 and 256, which are in constant communication with grooves 25I and 252 formed in sleeve 253'. Cross sections through the grooves 25I and 252 are shown more particularly in Figures 10 and 11, and it will be noted that these grooves communicate with pipes 253 and 254 respectively.

The pipes 253 and 254 run to opposite ends of a secondary valve 255, more particularly shown in Figure 10. This valve has a pressure port 256 which is connected to a branch line 251 of the previously described pressure line I58. The pressure from port 256 goes through hydraulic resistances 256 and 259, represented by reduced p0rtions formed on the valve plunger 260 at opposite sides of spool 26 I, which is normally central with respect to port 256. Annular grooves 282 and 263 formed at the end of the hydraulic resistances convey the fluid to interdrilled channels 264 and 

